The UV Excesses of Supernovae and the Implications for Studying Supernovae and Other Optical Transients

TL;DR

This paper investigates UV excesses in supernovae and shows that traditional blackbody models cannot fit these UV-rich spectra, but bolometric light curve modeling provides a better understanding of these phenomena.

Contribution

It introduces a method to model UV excess supernovae using bolometric light curves instead of blackbody spectral energy distributions.

Findings

UV excess supernovae cannot be fitted with blackbody models.

Bolometric light curve fitting provides better modeling of UV-rich transients.

The i model effectively fits the constructed bolometric light curves.

Abstract

Supernovae (SNe), kilonovae (KNe), tidal disruption events (TDEs), optical afterglows of gamma ray bursts (GRBs), and many other optical transients are important phenomena in time-domain astronomy. Fitting the multi-band light curves (LCs) or the synthesized (pseudo-)bolometric LCs can be used to constrain the physical properties of optical transients. The (UV absorbed) blackbody module is one of the most important modules used to fit the multi-band LCs of optical transients having (UV absorbed) blackbody spectral energy distributions (SEDs). We find, however, that the SEDs of some SNe show UV excesses, which cannot be fitted by the model including a (UV absorbed) blackbody module. We construct the bolometric LCs and employ the (cooling plus) \Ni model to fit the constructed bolometric LCs, obtaining decent fits. Our results demonstrate that the optical transients showing UV excesses cannot be fitted by the multi-band models that include (UV-absorbed) blackbody module, but can be well modeled by constructing and fitting their bolometric LCs.